It is known that adding fibers to cement, mortar, concrete, or similar compositions (referred to throughout as cement) will increase the flexular and tensile strength of the cured product. Additionally, the fibers prevent, minimize, or inhibit cracking in the cured cement.
Cement is defined as any mixture of fine-ground lime, alumina, and silica that will set to a hard product by admixture of water which combines chemically with other ingredients to form a hydrate. Mortar is defined as a type of adhesive or bonding agent that may be either inorganic or organic, soft and workable when fresh but sets to a hard, infusible solid on curing, either by hydraulic action or by chemical crosslinking. The chief ingredients of inorganic mortars are cement, lime, silica, sulfur, and sodium or potassium silicate. Concrete is defined as a conglomerate of gravel, pebbles, sand, broken stone, and blast-furnace slag or cinders, termed the aggregate, imbedded in a matrix of either mortar or cement, usually standard Portland cement in the United States.
The addition of fibers to a cement mixture, prior to pouring, will minimize or inhibit cracking in the cured cement product. Minimization and inhibition of cracks is one of the primary reasons for adding fibers to cement. As such, it is well known and desired to add various synthetic fibers or other fibrous materials to cement compositions, as the fibers result in a more desired cured cement product.
Fibers are typically added to cement mixers prior to pouring at a construction site. The fibers are available in bags that are added directly to the mixer, whereby the bags will dissolve in the cement mixture found in the mixer. As such, the bags are added by hand, by workers. Unfortunately, there is no verification concerning whether the proper number of bags were added to the cement mixture. For example, if a bag is dropped on the ground prior to mixing, it is likely that it or a replacement will not be added to the mix. Whether the fibers have been added in the correct amount cannot generally be verified. For this reason, it is desired to have a way to better control and monitor the addition of the fibers.
The method for adding the fibers is not automated, which contributes to the inaccurate addition of the fiber material to the cement material. For this reason, it is desired to have a method that allows for more accurate metering and addition of the fibers to the cement. Typically, a cement truck must be directed to a staging area other than where the cement is added for the bags of fibers to be added thereto. The fibers are added at a location away from where the cement is added. As such, the cement trucks line up and have cement added thereto, with the fibers then added at a different location for safety reasons. This can be time consuming and inefficient. It is desired to have a more efficient method for adding the fibers.
The fibers to be added to the cement typically have a low density and, as such, they tend to float. Conversely, some fibers are of a density such that they sink. Such characteristics make it difficult to readily mix the fibers into a water-based, aqueous solution. Consequently, the fibers are not pre-mixed with water prior to the addition of the fibers to the cement. For this reason, it is desired to have a carrier for use with the fibers, which allows for the suspension of the fibers and easy mixing in the cement. The carrier form should be other than a dry mix to ensure easier addition to the cement. It is especially desired to have fibers available in an aqueous form, whereby the fibers are suspended.
The storage container typically used to hold the fiber gel composition is a gravity-fed bin. Typical gravity-fed bins encounter “bin-hangup” problems, which include rat holing, bridging, arching, adhesion, and/or clogging. These “bin-hangups” limit the output efficiency of the materials fed through the gravity-bins, because of the clumping action by the material within the bin, in the present case the fiber gel composition. For this reason, it is desired to have a storage container configured to minimize “bin-hangups” and facilitate a method for adding the gel fiber composition to the cement.
Thus, it is desired to have a fiber composition which can be more easily added to cement. It is further desired to have a composition that can be easily metered and controlled by an automated process to ensure accurate addition. It is further desired to eliminate manual addition by workers of the fibers to the cement.